A winch is a warping cone having means for driving power, decelerating and braking, which may be used for winding and storing ropes with the help of the driving power. A winch also includes self-protection and traction components equipped on vehicles or ships with an axis perpendicular to a deck. Winches are usually used for rescuing in harsh environments such as snowy grounds, swamps, seashores or muddy roads. In other situations, winches may be used for clearing obstacles, dragging items and installing equipments. As a necessary safety device, winches are applied in various occasions of utilization such as military and police, oil, hydrology, environmental protection, forestry, transportation, public security, border control, fire emergency and other outdoor activities. Off-road vehicles, agricultural vehicles, ATV all-terrain vehicles, yachts, fire rescue vehicles, road wreckers and other special-purpose vehicles are among vehicles which are usually equipped with winches.
A Chinese patent number ZL201310063776.3 discloses a winch apparatus including a driving component, a transmission shaft, a deceleration mechanism, a clutch mechanism, and a roll tube. The driving component is connected to the transmission shaft. The deceleration mechanism is drivably connected to the deceleration mechanism through the roll tube. The deceleration mechanism is drivably connected to the roll tube through the clutch mechanism. The winch apparatus is characterized in that one end of the transmission shaft is slidably engaged with an output end of the driving component, a reset spring is disposed between the one end of the transmission shaft and the output end of the driving component, the reset spring surrounds the transmission shaft, one end of the reset spring is in contact with the output end of the driving component, the other end of the reset spring is in contact with a retaining ring connected to the transmission shaft. The clutch mechanism includes a pushing component which is in contact with the other end of the transmission shaft and used to push the transmission shaft in an axial direction, and a transmission component rotatably disposed on the transmission shaft which is used to drivably connect the roll tube and the deceleration mechanism by sliding axially with the transmission shaft.
Another winch of the prior arts is disclosed in Chinese Patent Number ZL201610473915.3 which enables a winch to work in multiple word modes such as a high speed mode, a low speed mode and an idle mode. The winch as disclosed comprises a motor, a transmission shaft, a roll tube, a first planetary wheel component, a second planetary wheel component, and a third planetary wheel component. A spline and a three-stage center wheel are disposed between the second planetary wheel component and the third planetary wheel component. The spline and the three-stage center wheel are moveable in response to movement of the transmission shaft. The winch as disclosed is operable in three work modes by moving the spline along with the transmission shaft. In a first work mode, the spline is drivably connected to both the second planetary wheel component and the third planetary wheel component. In a second work mode, the second planetary wheel is drivably connected to the second planetary wheel component. In a third work mode, the spline is drivably connected to both the second planetary wheel component and the three-stage center wheel. A resetting spring is connected to the three-stage center wheel which is used to push or reset the resetting spring. The winch comprises a work mode controlling mechanism to enable axial movement of the transmission shaft thereby switching the spline amongst the work modes described above. However, the winch as disclosed implements a spline to connect the second planetary wheel component, the third planetary wheel component and the three-stage center wheel. During switching of work modes, a spline incompletely engaged would cause stuck of the planetary gearbox and damage the inner structure of the winch.